Calma gobioophaga
Recently described from specimens collected in Arrábida (Calado & Urgorri, 2002). This species feeds exclusively on the eggs of Gobius species. To data, in Arrábida it has only been reported feeding on eggs of Gobius niger (Calado & Urgorri, 2002), but it has also been reported feeding on Gobius cobitis and G. bucchichii in the Mediterranean (Prkic et al, 2014), which also occur in Arrábida.
There is another species of the genus in Arrábida, C. glaucoides, which is less selective and feeds on eggs of several species of the fish in the genera Lepadogaster e Parablennius (Calado & Urgorri, 2002).
References: Calado, G. & Urgorri, V. (2002). A new species of Calma Alder & Hancock, 1855 (Gastropoda: Nudibranchia) with a review of the genus. Journal of Molluscan Studies 68(4), 311–317
Prkic, J.; Furfaro, G.; Mariottini, P.; Carmona, L.; Cervera, J.L., Modica, M.V. & Oliverio, M. (2014). First record of Calma gobioophaga Calado and Urgorri, 2002 (Gastropoda: Nudibranchia) in the Mediterranean Sea. Mediterranean Marine Science, 15(2), 423-428